Soon after you’ve had your first cup of rich dark hot chocolate in the city of Oaxaca (wa-ha-ka), you’ll be making plans for Mitla, one of the most important archaeological sites in Oaxaca (the name of the state/region, as well as the city).

Built around 800 BC by the Zapotecs (and the Mixtecs), an Indian race that followed the Mayans, the ruins of Mitla have remained remarkably well-preserved. The huge complex is laid out around a central, cross-like structure, with each facade of the "cross" featuring nine panels of mosaics--elaborate stone puzzle pieces perfectly fitted to one another.

Zapotec innovation in pre-Colombian timesWhen the Spaniards arrived in 1521, they assumed that because of the cross-shape of the structure, and the small cross-like designs in the mosaics, that earlier Europeans must’ve arrived before them and influenced the Zapotecs with Christianity. But of course there was no relation, as there had been no earlier arrivals, and the four directions of the cross have been seen universally in many cultures to represent the four sacred elements—fire, air, water, and wind—as well as the four directions.

Within the site’s walls and tunnels, the same wondrous feat of geometric patterns gracing the walls of a large, dark passageway (complete with a creepy little bat flying around), in which the symmetric patterns on one side directly correspond to the patterns opposite, as if you were holding up a mirror—an amazing feat of geometry and mathematics that took modern scientists and graphic designers eight months to duplicate with a computer.

Further excavations have revealed cylindrical quartz bars, perfectly rounded and carved, and inside: phosphorus. Do you know what that makes? LIGHT. Nearly 3000-year-old light bulbs, developed by ancient Mesoamericans!

Mitla is also unique because it’s one of the sites not overtaken and altered by the Aztecs. As such it is a unique monument to the ingenuity of the Zapotec and their harmonious successors, the Mixtecs. Mitla was never buried under earth or ash, which means you can still see signs of the original colors painted on some of the walls, preserved for years because of a combination of calcium and lemon/lime juices.

Mitla--every bit as memorable as that cup of dark hot chocolate you'll be sipping in nearby Oaxaca City.